The proposed project, entitled Exercise Prescription Toolbox for Depression: A Tailored Web-based Program (the "Toolbox"), is designed to help mental health practitioners provide counseling to patients with depressive disorders about physical activity and exercise. The primary target audience for the Toolbox is mental health practitioners who provide treatment for depressed adults. The goals of this website will be: 1) increase knowledge on the role of physical activity or exercise in the treatment of depression and co- morbidities; and, 2) increase counseling that addresses major barriers for physical activity and exercise with depressed patients. This Phase I application will develop an evidence-based content library to increase knowledge of mental health counselors about the role of exercise in alleviating symptoms of depression and non-psychiatric co-morbidities such as diabetes and cardiovascular disease. In the Phase I application we will also develop a theoretically based algorithm for providing tailored advice and homework assignments to depressed patients. This works builds on previous successful behaviorally based lifestyle physical activity studies and randomized trials of exercise to treat mild to moderate major depressive disorder (MDD). The specific aims of this project are to: (1) conduct a survey of community mental health providers to assess content knowledge; nature and level of current a) counseling advice for exercise and physical activity and b) use of computers and the Internet as part of this counseling; ratings of specific features of the proposed website; and whether these clinicians would be likely to use particular aspects of the proposed website as part of their current practice (2) develop a treatment algorithm and assessment tool for prescribing tailored physical activity or exercise; and,(3)develop a schematic web map, specifications document, and prototype to guide the Phase II production and testing. This application is for Phase I only and will answer questions about whether mental health counselors would find such a tool to be useful in their clinical practice, what features the algorithm needs to include and how these features should be organized for optimal use employing an Internet- based program. If key criteria are met in Phase I, Phase II will develop the website, conduct usability testing of the website, and assess whether mental health counselors in community settings increase counseling for physical activity or exercise with patients with depression disorders. The public health significance of the Exercise Prescription Toolbox is to improve counseling for physical activity by mental health practitioners with their depressed patients. Helping depressed patients to increase and maintain a regular program of physical activity can help alleviate symptoms of depression and improve other health outcomes related to heart health, cancer, diabetes, and physical functioning. [unreadable] [unreadable] [unreadable]